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1.
Aposematic animals advertise their unprofitability to potential predators with conspicuous coloration, occasionally in combination with other life-history traits. Theory posits that selection on functionally interrelated aposematic characters promotes the unidirectional evolution of these characters, resulting in an increase or decrease in the effectiveness of the signal. To test whether this prediction applies on a microevolutionary scale, the intra- and interpopulational variations in aposematic coloration, behaviour (which enhances the effectiveness of the coloration) and body size of newts, Cynops pyrrhogaster (Urodela: Salamandridae), were investigated. A parallel geographical mosaic of variation in aposematic coloration and behaviour among populations, independent of body size, was found. Newts on islands displayed more conspicuous aposematic traits than those on the mainland, both morphologically and behaviourally. There was no significant relationship between variation in coloration and behaviour within populations. Male newts displayed more conspicuous coloration than females. Surveys of potential predators suggest that variable natural selection at a local scale, such as predation pressure, may primarily be responsible for the microevolution of variable aposematic traits in newts.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 613–622.  相似文献   

2.
Historical relationships were inferred for the oriental lizards of the genus Takydromus Daudin 1802 (Lacertidae) on the basis of DNA sequences. Of the 17 species currently recognized for the genus, 13 species represented by 42 specimens from 29 localities were examined. Maximum-likelihood and maximum-parsimony analyses of data for 829 aligned sites from parts of the mitochondrial 12S and 16S rRNA genes yielded relationships that, while showing no substantial discrepancy with each other, were strikingly different from a currently prevailing phylogenetic hypothesis from a parsimony analysis of morphological characters. Based on the results of these molecular analyses, supplemented by results of the morphological analysis that offered robust evidence for positions of two additional species ( T. khasiensis and T. sylvaticus ), the following interrelationships were hypothesized as the most preferred phylogeny: ( kuehnei ( sexlineatus khasiensis ))( tachydromoides (( smaragdinus ( sauteri ( dorsalis sylvaticus ))) ( amurensis ((( formosanus wolteri ) hsuehshanensis )( toyamai ( septentrionalis stejnegeri )))))). These interrelationships indicate: (1) invalidity of Platyplacopus Boulenger 1917 , which was recently resurrected as a subgenus of Takydromus on the basis of the morphological analysis; (2) homoplasy in states of some morphological characters, such as green dorsal coloration, that were considered as synapomorphs of certain nodes in the morphological analysis; and (3) involvement of the genus in a series of vicariances in both the continental and insular parts of eastern Eurasia. Due to the paucity of available samples, phylogenetic status of T. intermedius and T. haughtonianus remain to be examined in future studies.  © 2002 The Linnean Society of London, Biological Journal of the Linnean Society , 76 , 493–509.  相似文献   

3.
Phylogenetics of Echinodorus (Alismataceae) based on morphological data   总被引:1,自引:1,他引:0  
Echinodorus (Alismataceae) is a genus of aquatic and semi-aquatic herbs naturally distributed from Argentina to the USA but commonly used as ornamentals in aquaria worldwide. The phylogeny of the genus was studied on the basis of 96 morphological characters. The analysis resulted in a single most-parsimonious tree supporting a polyphyletic origin of the genus. However, subgenus Echinodorus together with Echinodorus nymphaeifolius formed a clade. Two large clades can be recognized in Echinodorus s.s. , but previous subdivisions of the genus are not supported and some earlier proposed subspecific combinations were shown to be non-monophyletic. Addition of continuous characters coded as value ranges enhanced both the resolution and the support values of the tree. Hence, inclusion of continuous overlapping data is encouraged in phylogenetic studies.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 291–305.  相似文献   

4.
The taxonomic position of western Asian members of Gentiana sect. Pneumonanthe has long been a matter of conflict. In this paper, the six western Asian species currently recognized as belonging to sect. Pneumonanthe ( G. boissieri , G. calycina , G. freyniana , G. gelida , G. paradoxa , and G. septemfida ) are compared and their relationships established using a morphological phylogenetic analysis. Seed testa and flower and leaf morphological characters were studied and 11 characters were selected for a cladistic analysis. Euro-Siberian and Far Eastern taxa of sect. Pneumonanthe ( G. pneumonanthe and G. scabra ) were used as outgroups. Our results suggest the presence of two morphologically distinct clades within the western Asian gentians: a Septemfida and a Gelida clade. G. calycina and G. freyniana show close affinities to G. boissieri and G. gelida , and are distinct from G. septemfida s.l. Biogeographical aspects of the two groups are discussed.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 197–208.  相似文献   

5.
A cladistic analysis is performed using 94 morphological and biochemical characters for 42 genera to compare a phylogeny based on morphological data with those obtained using different genes ( rbc L, atp B, 18S RNA, mat K) or their combination with morphological data, and to understand the floral evolution within the expanded Brassicales (Capparales) relative to Sapindales and Malvales. The tree produced with morphological data is congruent with those obtained from macromolecular studies in obtaining a well-supported glucosinolate-producing clade and an expanded Sapindales. The combined analysis of the morphological and molecular characters is generally well resolved with support for many of the relationships. The inclusion of the fossil taxon Dressiantha demonstrates the value of inserting fossil evidence in phylogenetic analyses. However, the fossil appears to be related to the Anacardiaceae and not to the Brassicales. The core Brassicales are well supported by a number of synapomorphies, although the internal position of Tovariaceae and Pentadiplandraceae is not well resolved. Emblingiaceae appears to be related to Bataceae and Salvadoraceae. Several significant morphological characters are mapped on the combined trees and their evolutionary significance is discussed. Within Brassicales and Sapindales several well supported clades can be recognized which merit ordinal or subordinal status, putting the present orders at a higher level; these include: Tropaeolales, Setchellanthales, Batidales, Brassicales (Brassiciflorae), Burserales, Sapindales and Rutales (Sapindiflorae). The present scheme of affinities within the Brassicales corresponds well with a gradual morphological evolution in the order.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 453–494.  相似文献   

6.
Persistent questions concerning the warning coloration of unpalatable insects address whether the bright aposematic colour itself or its combination with a species-specific dark pattern is the key factor in their protection against insectivorous birds, and how chromatic polymorphism originates and is maintained in aposematics. In the present study, these questions were tested experimentally, using the birds Parus major , Parus caeruleus , Erithacus rubecula , and Sylvia atricapilla as predators, and chromatically polymorphic firebug Pyrrhocoris apterus : red wild form, white, yellow, and orange mutants (all four of them with the same black melanin pattern, the mutants differing in colour of pteridine pigments only) and the nonaposematic brown-painted wild form as prey. The results show that a specific colour is essential for the birds to recognize the specific aposematic prey; the melanin pattern is not sufficient. White mutants were no better protected than nonaposematic firebugs; red wild-type and orange mutants were equally well protected against all bird species; and the reaction of birds to yellow mutants was species-specific. An evolutionary scenario of 'recurrent recessive mutations' is formulated to explain the origin of colour polymorphism in some aposematics.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 88 , 143–153.  相似文献   

7.
We describe Centrolene bacatum , C. buckleyi , Cochranella posadae , and a new species of Cochranella from Yanayacu Biological Station on the Amazonian slopes of the Ecuadorian Andes. The new species differs from other species in Centrolenidae by a combination of characters, including reduced webbing between Fingers III and IV, and kidneys covered with white peritoneum. We summarize the current generic and infrageneric classification in Centrolenidae and discuss some of its problems. A phylogenetic analysis of morphological and behavioural data shows that the genera Centrolene and Cochranella might not be monophyletic; the genus Hyalinobatrachium and, in particular, the group H. fleischmanni seem to be monophyletic. However, an analysis with many more characters is needed to resolve the relationships of glass frogs.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 147 , 489–513.  相似文献   

8.
Few operational methods exist for delimiting species boundaries, and these usually require sampling strategies that are unrealistic for widespread organisms that occur at low densities. Here we apply molecular, morphological and ecological species delimitation criteria to a wide-ranging, fragmented group of Asian green pitvipers, the Popeia popeiorum complex. A mitochondrial DNA phylogeny for the group indicates two well-differentiated clades, corresponding mainly to northern and southern parts of its range. Strong phylogeographical structure within each clade suggests isolation in forest refugia during the Pliocene and a southward colonization of the Sunda islands during the Pleistocene. Multivariate analysis of morphological characters reveals a generally conserved pattern of geographical variation, incongruent with the recovered phylogenetic history. We compare groups delineated by mtDNA variation to morphological and ecological divisions in the complex, and discuss the implications of these for the taxonomy of the group. Discordance between species boundaries inferred from different criteria suggests that combining independent sources of data provides the most reliable estimation of species boundaries in organisms that are difficult to sample in large numbers.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 87 , 343–364.  相似文献   

9.
The adaptive significance of coloration in lagomorphs   总被引:3,自引:0,他引:3  
Lagomorph pelage coloration was matched to habitat type, geographical region, altitude and behaviour to explore the adaptive significance of coloration patterns in this little-studied order of mammals. Analyses were conducted with and without taking phylogeny into account. The former analyses were based on a weighted, phylogenetic supertree for all extant species of lagomorphs that we constructed using morphological and molecular data from 146 papers in the literature. Although our analyses represent an initial, somewhat crude investigation, several clear trends are evident. First, overall body coloration across lagomorphs tends to match the background as shown for pale and red coloration and perhaps seasonal pelage change. The case for countershading being a method of concealment is far less strong. Second, ear tips appear to have a communicative role since they are conspicuous in many different habitats. Third, hypotheses for tail tips having a communicative role, for extremities being dark for physiological reasons, and for Gloger's rule received only partial support.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 79, 309–328.  相似文献   

10.
Recent molecular analyses have demonstrated that the traditional Lucinoidea, comprising the extant families Lucinidae, Thyasiridae, Ungulinidae, Fimbriidae, and Cyrenoididae, is not monophyletic. Thyasiridae and Ungulinidae are unrelated to Lucinidae, a result corroborated by clear morphological differences between the groups. Chemosymbiosis in Thyasiridae and Lucinidae has been independently derived. Within the family Lucinidae, previous ideas of relationship and subfamilial divisions based on shell characters have little support from molecular results. Anatomical characters of the ctenidia, mantle gills, and posterior apertures have potential in phylogenetic analysis but rigorous analysis of shell characters is also needed. Although there is a good fossil record of Lucinidae throughout the Cenozoic and Mesozoic, in the Palaeozoic fossils are less frequent and most need reappraisal. The Silurian Ilionia prisca is probably the earliest fossil with convincing lucinid features, followed in the Devonian by Phenacocyclas and some Paracyclas species.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 421–438.  相似文献   

11.
Despite the considerable research that has focused on the evolutionary relationships and biogeography of the genus Bufo, an evolutionary synthesis of the entire group has not yet emerged. In the present study, almost 4 kb of DNA sequence data from mitochondrial (12S, tRNAVal, and 16S) and nuclear (POMC; Rag-1) genes, and 83 characters from morphology were analysed to infer a phylogeny of South American toads. Phylogenies were reconstructed with parsimony and maximum likelihood and Bayesian model-based methods. The results of the analysis of morphological data support the hypothesis that within Bufo , some skull characters (e.g. frontoparietal width), correlated with the amount of cranial ossification, are prone to homoplasy. Unique and unreversed morphological synapomorphies are presented that can be used to diagnose recognized species groups of South American toads. The results of all phylogenetic analyses support the monophyly of most species groups of South American Bufo . In most DNA-only and combined analyses, the South American (minus the B. guttatus and part of the ' B. spinulosus ' groups), North American, Central American, and African lineages form generally well-supported clades: ((((((((South America) (North America + Central America)) Eurasia) Africa) Eurasia) South America) West Indies) South America). This result confirms and extends prior studies recovering South American Bufo as polyphyletic. The biogeographical results indicate that: (1) The origin of Bufo predates the fragmentation of Gondwana; (2) Central and North American species compose the sister group to a large, 'derived' clade of South American Bufo ; and (3) Eurasian species form the sister group to the New World clade.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 146 , 407–452.  相似文献   

12.
Species of Eunice are distributed worldwide, inhabiting soft and hard marine bottoms. Some of these species play significant roles in coral reef communities and others are commercially important. Eunice is the largest and most poorly defined genus in Eunicidae. It has traditionally been subdivided in taxonomically informal groups based on the colour and dentition of subacicular hooks, and branchial distribution. The monophyly of Eunice and of its informal subgroups is tested here using cladistic analyses of 24 ingroup species based on morphological data. In the phylogenetic hypothesis resulting from the present analyses Eunice and its subgroups are paraphyletic; the genus may be divided in at least two monophyletic groups, Eunice s.s. and Leodice , but several species do not fall inside these two groups. Most of the traditional characters used in the taxonomy of Eunice are homoplasies; however, characters used for the first time in this study, such as certain jaw characters and characters derived from a close examination of chaetal variation along the body, are promising sources of phylogenetic signal.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 150 , 413–434.  相似文献   

13.
Previous phylogenetic analyses of Orchidaceae subtribe Orchidinae resulted in the proposal to classify Coeloglossum viride (L.) Hartman within the genus Dactylorhiza in order to maintain its monophyly. In this paper, we report some results that contradict previous studies regarding the monophyly of the traditional Dactylorhiza and its phylogenetic relationship with Coeloglossum. Our results, which combine sequences of the internal and external transcribed spacers of the nuclear ribosomal DNA, support the monophyly of Dactylorhiza , with Coeloglossum being a sister clade. The position of C. viride in the phylogenetic tree, and the considerable morphological differences with respect to Dactylorhiza , incline us to retain both lineages as distinct genera.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 261–269.  相似文献   

14.
The systematic biology of the subgenus Daphnia s . s . remains confused. Prior attempts at resolution used chiefly postabdominal claw morphology, chromosome numbers and rRNA gene sequences as characters for higher-level relations. Still, several taxa, such as Daphnia curvirostris Eylmann, 1878, have unclear affiliations. We addressed the position of D. curvirostris in this genus by estimating phylogenetic trees from a rapidly evolving protein coding gene (ND2), conducting broad geographical comparisons and carrying out detailed morphological comparisons. The Japanese ' curvirostris' was found to be a new divergent lineage in the subgenus Daphnia , and to possess distinctive morphological characteristics from D. curvirostris . We described this new species as Daphnia tanakai sp. nov. , and redescribed D. curvirostris . The polymorphic postabdominal claw morphology and the distinctive chromosome number of D. tanakai sp. nov. provided evidence for rapid evolution of these traits. Our new morphological, chromosomal and genetic assessment of Daphnia weakened the argument for division of the subgenus Daphnia ( Daphnia ) O. F. Müller, 1785 sensu Johnson, 1952, into two further subgenera.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 146 , 385–405.  相似文献   

15.
The sepiids are characterized by their cuttlebone or sepion, an internal shell resulting from secondary mineralization of a chitinous 'gladius'. The various species are identified using a combination of shell criteria and 'soft-part' characters. Using mitochondrial genes, we established phylogenetic relationships of sepiids including the three accepted genera ( Sepia , Sepiella , Metasepia ) and a species complex of uncertain status ( Doratosepion ). We showed the Sepia genus to be paraphyletic and found no direct correlation between geographical distribution and systematics. We mapped, on the molecular tree, shell characteristics commonly used as reliable diagnostic criteria for taxonomy. Due to the plasticity of the shell, these characters did not appear phylogenetically informative. In an attempt to define systematic categories related to phylogenetic relationships, new clear synapomorphies need to be established for each genus, necessitating a revision of the genus Sepia .  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 139–150.  相似文献   

16.
Cerdia is a poorly understood genus of minute cushiony plants endemic to Mexico that is traditionally placed in subfamily Paronychioideae, tribe Polycarpeae (Caryophyllaceae). Morphological observations and phylogenetic analysis of ITS DNA sequences were carried out to determine the number of species, heretofore controversial, that constitute the genus as well as its position within Caryophyllaceae. Samples of Cerdia were collected through its entire range of distribution and together with previous specimens were used in morphological analyses. Nineteen terminal taxa were considered in a phylogenetic analysis with representatives of the different lineages in Caryophyllaceae. Results indicated that Cerdia is a monotypic genus, including only one variable species, C .  virescens , but its phylogenetic affinities remain doubtful.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 152 , 1–13.  相似文献   

17.
A new method is proposed which uses transitions among acts in non-stereotyped behavioural sequences as phylogenetic characters. This method is derived from the event-pairing method designed for the phylogenetic study of developmental sequences and from ethological analyses of transition matrices. It is applied to study the phylogenetic relationships within a well-known group, the presocial Zetoborinae cockroaches. The analysis is carried out with three data sets: a behavioural data set with transitions among acts in behavioural dyadic sequences, together with morphological and molecular data sets. Non-stereotyped behaviour proved to be phylogenetically informative and to display low homoplasy. This new method opens an avenue for studying the evolution of behaviour in the framework of phylogenetic analysis, which was restricted until now to the study of stereotyped sequences and/or isolated features involved in courting or building activities.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 853–867.  相似文献   

18.
We analysed the putative hybrid zone between the ground beetles Carabus lewisianus Breuning and C. albrechti Morawitz from the Kanto and Tanzawa Mountains in central Honshu, Japan, using morphological, genetic, and behavioural data. Canonical discriminant analysis of three external and five genital morphological characters revealed an apparent morphological gap, suggesting restricted sympatry in the contact zone. RFLP and molecular phylogenetic analyses of the mitochondrial gene ND5 revealed that haplotypes originating from C. lewisianus introgressed extensively into C. albrechti . Fitting tanh curves to morphological (external and genital) and genetic characters showed differential cline widths and centres, suggesting stronger selection for genital morphology with narrower cline widths, and extensive introgression of the nuclear genes responsible for external characters relative to those controlling genital morphology into the range of C. albrechti . Linkage disequilibria between the morphological characters did not differ from zero, suggesting sufficient recombination occurred in the zone but the effect of small sample sizes was not negligible. Mate choice trials demonstrated that males showed a weak but not significant preference for conspecific mates. We interpret these patterns as evidence for (1) partial reproductive isolation presumably by postmating processes; (2) selection against intermediate genital morphologies, and (3) independent responses of the characters to different evolutionary forces that may cause movement of genital clines and introgression of the mitochondrial gene and external morphology. The movement of the boundaries may have resulted in the particular species distribution patterns in the study area.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 86 , 79–94.  相似文献   

19.
In a previous study of the phylogeny of basal Hymenoptera, Vilhelmsen (2001; Zool. J. Linn. Soc . 131 : 393–442) compiled an extensive morphological data matrix for a phylogenetic analysis of basal Hymenoptera, comprising 38 hymenopteran genera. In this study, his characters are revised. This results in a cladogram whose relationships largely agree with those proposed by Vilhelmsen, except that the relationships at the base of the Hymenoptera are unresolved. The revised data matrix is expanded by 17 sawfly and three apocritan taxa. Moreover, 112 new morphological characters from different parts of the larval and adult morphology are also added to the data matrix, including 82 from a recent study of the terminal abdominal segments of male Hymenoptera. The addition of the new characters leads to Xyelidae, again, being the sister-group of all other Hymenoptera. The relationships among the sawfly families as proposed by Vilhelmsen are confirmed, except that the relationships among Syntexis , Siricidae and Xiphydriidae + Vespina are unresolved and that the monophyly of Apocrita is not convincingly supported. A separate analysis is performed which includes all extant genera of Xyelidae. The internal phylogeny of Xyelidae is determined as (( Macroxyela Megaxyela ) Xyelecia ( Xyela Pleroneura )).  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 79 , 209–243.  相似文献   

20.
A new dyrosaurid is described from the Ypresian of the phosphatic deposits of the Oulad Abdoun Basin of Morocco. It is based on numerous cranial and postcranial remains, allowing an almost complete reconstruction. This new Dyrosaurus species, Dyrosaurus maghribensis sp. nov. , is currently only known from Morocco. It differs from D. phosphaticus , present in contemporaneous levels of Algeria and Tunisia, by several autapomorpies, including a smooth dorsal margin of the parietal and widely opened choanae. A phylogenetic analysis, using 47 taxa and 234 morphological characters, shows the dyrosaurids as the sister taxon of pholidosaurids, which include Elosuchus , Sarcosuchus , Terminonaris and Pholidosaurus , and the thalattosuchians. Goniopholididae is a non-monophyletic group; however, if dyrosaurids are not included in the analysis, the result differs and the goniopholidids form a distinct clade. If Thalattosuchia is excluded, both Goniopholididae and Pholidosauridae become paraphyletic assemblages. Thus, phylogenetic problems remain with respect to longirostrine clade, and more attention should be paid to resolving their evolutionary relationships amongst the crocodyliforms.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 603–656.  相似文献   

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